5 U.S. Code § 808 - Effective date of certain rules

(1)any rule that establishes, modifies, opens, closes, or conducts a regulatory program for a commercial, recreational, or subsistence activity related to hunting, fishing, or camping, or

(2)any rule which an agency for good cause finds (and incorporates the finding and a brief statement of reasons therefor in the rule issued) that notice and public procedure thereon are impracticable, unnecessary, or contrary to the public interest,

shall take effect at such time as the Federal agency promulgating the rule determines.